The number of personal vehicles in China is growing daily. When cars are parked under the sun, the metal plates of the car body rapidly absorb heat, causing the cabin temperature to rise quickly, which leads to more energy consumed in reducing such high temperatures. Therefore, there is a wide demand for vehicle sunshades, of which various types are available. For example, Chinese Patent Application No. 01228188.3 presents a vehicle sunshade that is attached to a supporting stand on a car roof with left and right piston valves also attached to the roof. The piston shafts are connected to the sunshade fabric and are controlled hydraulically. In addition, Chinese Patent Application No. 200310101651.1 presents a vehicle sunshade utilizing a suction cup for securing a supporting stand with the sunshade fabric attached. The first type of sunshade mentioned utilizes hydraulics with the sunshade fabric installed inside the axle, which is likely to cause jamming when leading the fabric out; the structure for the sunshade is also overly complicated, which requires greater driving power. The second type is simpler in structure, but bulky in size; therefore, despite the fact that the suction cup is arranged on the car trunk and the area of sunshade is greater, the sunshade fabric is supported by the supporting stand fixed to the car roof, resulting in reduced cover for the car window areas.
To overcome the drawbacks associated with the above types of vehicle sunshades, the Applicant have designed a vehicle sunshade after much research and development. The sunshade is disclosed in Chinese Patent No. 200720312179.X and is comprised of a supporting stand and sunshade fabric secured to the supporting stand. The supporting stand includes a frame on the car roof and moveable supporting shafts that are attached to the frame. At least one supporting shaft is attached per side on the front, rear, left and right sides of the frame. The sunshade fabric is then attached to the support shafts on the four sides of the frame so that it can provide cover for the car windows. In addition, by supporting the sunshade fabric with a raised stand, cover can be achieved while maintaining air flow. Since the supporting shafts are movable, they can be turned and folded into the frame. The simple structure of the system allows the supporting shafts to be placed on the car roof when the sunshade is not in use; when it comes time to use the sunshade, the shafts can then be repositioned. One can see that the vehicle sunshade designed by the Applicant can solve the drawbacks associated with the two aforementioned types of vehicle sunshades. However, during practical use, it has been found that the sunshade fabric at the four corners cannot be easily folded for storage due to difficulties during the turning and folding of the supporting shafts. The folding and storing requires manual manipulation, which makes the system somewhat inconvenient in practical use and presents difficulties for the addition of automatic controls.